Run a find or locate or whereis command to see where it is.
find / -name xorg.conf
The following thread in Ubuntu forums talks about hunting for it, with examples of other commands. I only know how to use find. I know it is not our OS but basic Linux is basic Linux.
http://ubuntuforums.org/showthread.php?t=829892
If you google, there are a lot of pages with Xorg.conf examples.
I know zilch about xorg but am answering you as no one else has in a few days. One site suggested the following command:
Xorg -configure
Maybe also try looking for Xorg.conf instead of xorg.conf, that could find it at Linux is case sensitivite.
FORUM TIP: To view someone's posting history, sign in, click on their user name, then on "Search User's Posts." || Running ArchLinuxArm on Model 2B and 512MB Model B